1) Field of the Disclosure
The disclosure relates generally to fixtures, systems and methods for holding structures during manufacturing operations, and more particularly, to improved fixtures, systems and methods using a phase changing material to hold parts, such as workpieces, during manufacturing operations.
2) Description of Related Art
In the manufacture of component parts and structures for aircraft, spacecraft, rotorcraft, watercraft, or other vehicles or structures, fixtures are often utilized to hold or support parts or workpieces during manufacturing processes or operations performed on the parts or workpieces. Such manufacturing processes or operations may include, for example, machining, milling, cutting, drilling, trimming, shaping, and other manufacturing processes or operations. Typically, either solid fixtures or flexible fixtures may be used to hold or support parts or workpieces during such manufacturing processes or operations.
Solid fixtures consisting of a non-reconfigurable material shaped to fit a nominal part and designed to hold the part via vacuum or clamping devices are known. However, such solid fixtures do not account for part variation, and parts may need to be manipulated and flexed to fit into a solid fixture. Each different part class may require its own solid fixture. This may result in increased manufacturing, maintenance, and storage costs for such solid fixtures. Moreover, lift assist equipment may be required if the solid fixture is heavy or bulky, and such lift assist equipment may be expensive to use and set up. Further, changing the solid fixture for each different part class may require increased time and effort, which, in turn, may result in overall increased manufacturing costs.
Flexible fixtures consisting of multiple independent actuators that can be adjusted to fit the shape of the part being held and that require a sophisticated controller to drive such actuators to programmed positions are known. However, such flexible fixtures may be expensive, complex, have decreased reliability, and may be physically large in size, thus requiring increased area or floor space. In addition, flexible fixture systems that can be reconfigured may require a large number of motorized actuators, controlling mechanisms, and electronics associated with each independent actuator. This may result in increased costs and complexity and decreased reliability.
Another known fixturing system includes the use of a material or device that freezes or cures around a workpiece or part, for example, freeze chucks, to hold or support the part or workpiece. However, although freeze chucks are adaptable to different part shapes, they may only be feasible for use with small parts and not for use with large parts. For example, the time required to freeze the holding material may be, for example, 90 (ninety) seconds for small parts, but may significantly increase with the amount of holding material that needs to be frozen for larger parts. This may result in increased manufacturing time.
Accordingly, there is a need in the art for an improved adjustable part holding fixture, system and method that is simple to install, use and service, compact in size, low cost, and reliable, and that provide advantages over known fixtures, systems and methods.